Electronic gavel



Jan. 8, 1963 c. B. SCHMERTZ 3,072,898

ELECTRONIC GAVEL Filed Aug. 22, 1961 FIG.2

as 12 RA. -3% A AUDIO SYSTEM-RA AMPLIFIER SYSTEM 6 76 34 70 (l .MICRO- y 66 PHONE 18 FIG.3

AUDIO AMPLIFIER MOTOR INVENTOR.

Charles B. Schmerfi ATTORNEY Filed Aug. 22, 1961, Ser. No. 133,246 6 Claims. (Cl. s40-3s4 This invention pertains to sound generating and amplifying means and more particularly to an electronic gavel.

Conventional gavels comprising a hammer and a sounding board can generate a sound of limited amplitude. While it is true the sound volume can be increased by more violently striking the sounding board with the hammer, there is still an upper limit tothe volume of sound. In assembly rooms of large volume or in groups having a high noise level, conventional gavels are often ineffective. Even though there have been attempts to place a speakers microphone close to a conventional gavel, such makeshift combinations are generally unreliable since the speaker usually moves the microphone away from the gavel and toward his mouth.

It is therefore an object of the invention to provide a gavel which requires a minimum physical exertion by the user.

It is a further object of the invention to provide a gavel which can generate any desired volume of sound.

It is another object of the invention to provide a gavel which is audible in noisy assembly halls and still requires a minimum of exertion by the user.

Briefly, in accordance with the invention, a gavel is provided comprising a motor driven hammer mean whose operation is controlled by a switching means. A sounding board means is placed opposite the hammer means so that when the hammer means is operated it strikes the sounding board means. An electromechanical transducer such as a pick-up is fixed in such a position with respect to the sounding board to pick up the sound generated when the hammer means strikes the sounding board means. The pick-up may be connected via a signal amplifying means to a speaker or to a public address system.

It should be noted that such a gavel is ideally suited for court rooms, conventions, legislative assemblies and all places where judicial, legislative and corporate business is administered.

Other objects, features and advantages of the invention will be apparent from the following detailed description of the invention when read with the accompanying drawings wherein:

FIGURE 1 shows an external view of the gavel of the invention;

FIGURE 2 is a view of the gavel of FIG. 1 wherein portions of the housing have been deleted to reveal the components of said gavel;

FIGURE 3 shows the power circuit diagram of the gavel; and

FIGURE 4 shows the signal circuit diagram of the gavel.

Referring to FIGURE 1, an external view of the gavel is shown enclosed by a housing 12. Passing through the front wall 14 of housing 12 i a spring-return pushbutton switch 16 and an amplifier volume control and on-oif switch 18. Disposed in the right side wall 20 are output jacks 22 to permit the plugging in of a public address system input cable, and an entry port 24 for a power cable 26. A heat escape grille 30 is disposed in the top wall 28. Connected to back wall 32 is a conventional speaker 34 which is shown via the broken away portion of top wall 23 for convenience. In general, with the power cable 26 plugged into a conventional A.C. outlet and switch 18 in the on position, and a user pushes switch 16, a gavel sound is transmitted by speaker 34 and trite States atent 0 ice an electrical signal representing the gavel sound is available.

It should be noted that as long as power cable 26 is plugged into a conventional AC. outlet an electrical signal representing a gavel sound will be transmittable from jacks 22 whenever push-button switch 16 is depressed. Switch 18 only controls the transmission of sound by speaker 34.

The gavel 10 will now be described in greater detail with reference to FIGURE 2. Disposed on the inner side of front wall 14 is a conventional audio amplifier 36 shown employing vacuum tubes. It should be noted that transistors could be conveniently employed. The remaining components of the audio amplifier 36 such as the resistors and capacitors are disposed on the underside of chassis 38. Disposed on a cork mat 46 which is fixed to bottom wall 48 is motor 40 and gear box 42. Gear box 42 connected to motor 40 by shaft 44 provides speed reduction and change of direction of rotary motion which is applied to cams 50 coupled to shaft 52 of gear box 42. Gear box 42 may also include a one revolution clutch. A hammer means 54 is also disposed on bottom wall 48. Hammer means 54 includes a resilient portion 56, a hammer head 58 and a cam follower arm 61 which is so disposed so as to be engaged by cams 50 during a portion of the rotation cycle of shaft 52. Sounding board 60 is fixed adjacent hammer means 54 by virtue of standofi 62 which is screwed to bottom wall 48. Spring 64 which connects sounding board 60 to gear box 42 is provided to minimize vibration on sounding board 60 and hammer 53 when they hit. Pick-up 66 is fixed to sounding board 60. Barrier strip 68 may be provided to facilitate the connection of the signal leads 70 of pickup 66 to the output jacks 22 and audio amplifier 36.

The operation of the gavel 10 will now be described in detail. When power cable 26 is plugged into an AC. outlet, power is supplied to audio amplifier 36 and via switch 16 which normally open to motor 447. See FIG. 3. When switch 16 is closed the AC. power energizes motor 46, causing shaft 44 (FIG. 2) to rotate. This rotation causes gear box 42 to drive shaft 52 in a counter-clockwise direction. During a portion of the cycle of rotation, earn 50 engages cam follower arm 61 drawing hammer head 53 away from sounding board 66. As cam follower arm 61 drops off cam 50 the resilient portion 56 drives hammer head 58 to strike sounding board 60. The resulting sound is transduced by pick-up 66 to an electrical signal which is fed via lines 70 to outlet jacks 22 by lines 72 and to audio amplifier 36 by lines 74 (see also FIG. 4). If switch 18 is in the on position, the signal is amplified and fed via lines 76 to speaker 34 where it is transduced to an audibly perceptive sound whose volume is controlled by the potentiometer portion of switch 18.

There has been shown an improved gavel which by employing an electrically operated hammer which strikes a sounding board upon which is mounted a pick-up that is connected to amplifying means which permits the generation of any level of sound with a minimum of physical effort by the user.

There will now be obvious to those skilled in the art, many modifications and variations which satisfy many or all of the objects and which gain many of the advantages but which do not depart from the spirit of the invention as defined by the appended claims.

What is claimed is:

l. A gavel comprising a source of electrical power, an electrically operated rotary power generator including a shaft, a manually operated switch for connecting said source of power to said electrically operated rotary power generator, a cam coupled to said shaft, a hammer means having a resilient portion, a hammer head and a cam follower arm, said cam follower arm being positioned for engagement with said cam so that as said cam rotates said cam follower arm engages said cam and'withdraws said hammer head whereby a stress is created in said resilient portion and when said cam follower disengages said cam the stress created in said resilient portion propels said hammer head, a sounding board fixed opposite said hammer head and so positioned to be struck when said hammer head is propelled, a pick-up means fixed in close proximity to said sounding board, signal amplifying means connected to said pick-up means, and a speaker connected to said signal amplifying means.

2. The gavel of claim 1 wherein said pick-up means is mechanically connected to said sounding board.

3. A gavel comprising a source of electrical power an electrical motor, a manually operated switch for connect ing said source of power to said electrical motor, a gear box having a shaft, means for mechanically coupling said gear box to said electrical motor, a cam coupled to said shaft, a spring biased cam operated hammer means positioned with respect to said cam so that as said cam rotates said spring biased cam operated hammer means is retracted under stress and then released, a sounding board resiliently mounted opposite said spring biased cam operated hammer means and so positioned to be struck when said spring biased cam operated hammer means is released after having been retracted, damping means for damping said resiliently mounted sounding board after having been struck, a pick-up means fixed in close proximity to said sounding board, signal amplifying means connected to said pick-up means, and a speaker connected to said signal amplifying means.

4. The gavel in claim 3 wherein said pick-up means is mechanically connected to said sounding board.

5. A gavel comprising a source of electrical power, an electrical motor, a manually operated switch for connecting said source of power to said electrical motor, a one revolution gear box having a shaft, means for mechanically coupling said gear box to said electrical motor, a cam coupled to said shaft, a hammer means having a blade type resilient portion, a hammer head and a cam follower arm, said cam follower arm being positioned for engagement with cam so that as said cam rotates said cam follower arm first withdraws said hammer head to exert a stress by fiexure on said blade type resilient portion and upon disengagement said blade type resilient portion propels said hammer head, a sounding board resiliently mounted opposite said hammer head and so positioned to be struck when said hammer head is propelled by said blade type resilient portion, a spring including one fixed end, means for connecting the other end to said sounding board whereby vibrations in said sounding board are damped after having been struck by said propelled hammer head, a pick-up means fixed to Said sounding board, signal amplifying means connected to said pick-up means, and a speaker connected to said signal amplifying means,

6. The gavel of claim 5 including means to connect said pick-up means to an external public-address system.

References Cited in the file of this patent UNITED STATES PATENTS 2,286,587 Sundt June 16, 1942 2,588,195 Rowe Mar. 4, 1952 2,971,187 Marr et a1. Feb. 7, 1961 3,002,187 Spear Sept. 26, 1961 

1. A GAVEL COMPRISING A SOURCE OF ELECTRICAL POWER, AN ELECTRICALLY OPERATED ROTARY POWER GENERATOR INCLUDING A SHAFT, A MANUALLY OPERATED SWITCH FOR CONNECTING SAID SOURCE OF POWER TO SAID ELECTRICALLY OPERATED ROTARY POWER GENERATOR, A CAM COUPLED TO SAID SHAFT, A HAMMER MEANS HAVING A RESILIENT PORTION, A HAMMER HEAD AND A CAM FOLLOWER ARM, SAID CAM FOLLOWER ARM BEING POSITIONED FOR ENGAGEMENT WITH SAID CAM SO THAT AS SAID CAM ROTATES SAID CAM FOLLOWER ARM ENGAGES SAID CAM AND WITHDRAWS SAID HAMMER HEAD WHEREBY A STRESS IS CREATED IN SAID RESILIENT PORTION AND WHEN SAID CAM FOLLOWER DISENGAGES SAID CAM THE STRESS CREATED IN SAID RESILIENT PORTION PROPELS SAID HAMMER HEAD, A SOUNDING BOARD FIXED OPPOSITE SAID HAMMER HEAD AND SO POSITIONED TO BE STRUCK WHEN SAID HAMMER HEAD IS PROPELLED, A PICK-UP MEANS FIXED IN CLOSE PROXIMITY TO SAID SOUNDING BOARD, SIGNAL AMPLIFYING MEANS CONNECTED TO SAID PICK-UP MEANS, AND A SPEAKER CONNECTED TO SAID SIGNAL AMPLIFYING MEANS. 